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XYZ mesons

XYZ News from Belle. XYZ mesons. Stephen L. Olsen, Univ of Hawai’i QWG 2006 June 26-30, Brookhaven. B-factories are Charmonium factories. c c production mechanisms @ a B factory: B meson decays e + e - annihilation gg collisions e + e - radiative return (isr).

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XYZ mesons

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  1. XYZ News from Belle XYZ mesons Stephen L. Olsen, Univ of Hawai’i QWG 2006 June 26-30, Brookhaven

  2. B-factories are Charmonium factories cc production mechanisms @ a B factory: • B meson decays • e+e- annihilation • gg collisions • e+e- radiative return (isr)

  3. cc production in B decays J = 0 or 1 j=½ j=½ Spectator model says Jcc= 0 or 1 should dominate exclusive BK(cc) decays.

  4. Allowed decays all have Bf~10-3from PDG2004 hcK 0.9 x10-3 J/yK 1.0 x10-3 J/yK* 1.4 x10-3 J/yK12701.8 x10-3 y’K 0.7 x10-3 y’K* 0.9 x10-3 cc0K 0.6 x10-3 cc1K 0.7 x10-3 BK cc(J=2) still not seen

  5. e+e- J/y + (cc) J/y hc’ cc0 X hc X (almost) always contains (cc) C(X) = +1 M(X) consistent with bkg

  6. gg DD JPC = 0++, 2++ e+e- g (cc) cc JPC = 1--

  7. XYZ particles in Belle • X(3872) • p+p- J/y in BKp+p-J/y • Z(3930) • DD in gg DD • Y(3940) • wJ/y in BK wJ/y • X(3940) • e+e-J/y X & e+e-  J/y DD* • Y(4260) • p+p-J/y in e+e-g p+p- J/y NEW

  8. gg  Z(3931) DD at Belle sin4q (J=2) Belle PRL 96, 082003 (2006) 4111 evts (5.5) M=3931 4  2 MeV =208 3 MeV M(DD) GeV Matches well to cc2’ expectations

  9. Z(3930): candidate for the cc2’ M= 3931 MeV is ~45 MeV low G=20MeV too narrow? 3931 Masses from Barnes, Godfrey & Swanson PRD 72, 054026 (2005)

  10. e+e- J/yX(3940) e+e-J/y + X hep-ex 0507019 submitted to PRL

  11. X(3940)D*D seen(DD & wJ/y not seen) B(DD)<41% B(D*D)>45% From X(3940) → D*D: M = (3943 ± 6 ± 6) MeV G < 52 MeV at 90%CL

  12. Is the X(3940) the hc”? M= 3943 MeV is ~150 MeV low G<52MeV too narrow? 3940

  13. X(3872) in BKp+p-J/y y’p+p-J/y X(3872)p+p-J/y PRL 91, 262001 M(ppJ/y)

  14. Also seen in pp X(3872) D0 CDF 11.6s X(3872) PRL 93, 072004 (2004) PRL 93, 162002 (2004) Production properties similar to those of the y’ hep-ex/0406022

  15. C=+1 is established M(pp) looks like a r X(3872)gJ/y seen in: CDF PRL 96 102002 Belle hep-ex/0505037 Belle & X(3872)”w”J/y seen Belle

  16. ereJ/y k(erxeJ/y) 0++ 0-+ Ruled out by Belle qlp y c2/dof=34/9 c2/dof = 34/9 |cosq| |cosqlp| |cosy| rule out 0++ & 0 -+

  17. Angular analysis from CDF 1++ or 2-+ Ilya Kravchenko: FPCP06

  18. Belle: Threshold peak in BKD0D0p0 Belle hep-ex/0606055  today! M(DDp) DE +0.7 -1.7 M=3875.4  0.7  0.8 MeV Br(BKX)Bf(XD0D0p0 ) = (1.27  0.31 )x10-4 +0.22 -0.39 Br(XD0D0p0) Br(Xp+p-J/y) ~ 10

  19. Comments on the D0D0p0 mass peak PDG MX3872: 3871.2  0.5 MeV ~2s discrepancy PDG05  2xPDG error on mD0 (could be  2.0 MeV) +0.7 -1.7 Fitted M: 3875.4  0.7  0.8 MeV DD* “Binding Energy?”: Here error on mD0 drops out +0.7 -1.7 M–(mD0+ mD*0) = +4.3  0.7 MeV Nominally ~2.3sabove D0D*0 threshold (but errors are non-Gaussian)

  20. X(3872) has no satisfactory cc assignment 3872 cc1’ Br(gJ/y) too small & Br(rJ/y) too big hc2 • hc2rJ/y ispin forbidden • D0D0p0 @ thresh. suppressed • BKcc(J=2) suppressed

  21. Y(3940) in BK wJ/y M≈3940 ± 11 MeV G≈ 92 ± 24 MeV G(Y3940 wJ/y)> 7 MeV (an SUF(3) violating decay) ~ this is 103 x G(y’  hJ/y) (another SUF(3) violating decay) if the Z(3930) is the cc2’ the Y(3940) mass is too high for it to be the cc1’ M(wJ/y) MeV PRL94, 182002 (2005)

  22. Is there a cc slot for Y(3940) ? hc” Mass is low cc1’ Can M(cc1’)>M(cc2’)? 3940 3931 cc0’ “ “ “ “

  23. 233 fb-1 e+e- gisr Y(4260) at BaBar BaBar PRL95, 142001 (2005) Not seen in e+e- hadrons X.H. Mo et al, hep-ex/0603024 Y(4260) 4260 BES data s(e+e-+p-J/)~50pb G(Y4260p+p- J/y) > 1.6MeV @ 90% CL 4260

  24. 13.3 fb-1 BaBar CLEO III N 125  23 (~8) 14.1 +5.2 (4.9) -4.2 Mass (MeV) 4259  8 +2 4283+17 4 -16 -6 Width (MeV) 88  23 +6 70 +40 5 -25 -4 Y(4260) at CLEO-III ISR (1S)-(4S) 13.3 fb-1 Consistent results R.Poling @ Charm 2006

  25. Y(4260) at Belle M=4295  10 +11 MeV G = 133  26 +13 MeV -5 Select e+e- p+p-ℓ+ℓ- +X; Nchg=4 Mℓ+ℓ-=MJ/y30MeV; pJ/y>2 GeV; Mpp>0.4GeV -6 | data  4.2<MppJ/y<4.4 Preliminary MC MX For y’p+p-J/y in the same data: M(y’) = 3685.3  0.1 MeV (PDG: M(y’)=3686.09  0.04)

  26. BaBar vs CLEO vs Belle -4.2 -5 -6 -16 -6 -4 -25 ~2.5s different “Full” report from Belle at ICHEP in Moscow

  27. No 1-- cc slot for the Y(4260) X.H. Mo et al, hep-ex/0603024 4280 4280

  28. DD** threshold in relation to the “Y(4260)” D** spectrum No obvious distortions 4.28-mD M(p+p-J/y) GeV

  29. summary • Z(3931) (ggDD) • Probably the cc2’ • X(3940) (e+e- J/y X) • C=+1 • Could be the hc” (albeit with some stretching) • X(3872): • JPC = 1++ • Br(Xp+p- J/y) large • Br(XD0D0p0) seen; ~ 10xBr(Xp+p-J/y) D*D

  30. 233 fb-1 summary cont’d • Y(3940) • G( Y3940 wJ/y) >7 MeVtoo large for charmonium • Mass too low for a hybrid • “Y(4260)” • Confirmed by Belle but at a higher mass • G(y4260p+p-J/y)>1.6 MeValso very large • JPC=1--, but not seen in e+e- hadrons - Straddles the D**D threshold, but with no obvious distortions to the ppJ/y line-shape

  31. (mine, not Belle’s) conclusions • There is a new hadron spectroscopy in the 3.5~4.5 GeV mass region • Maybe more than one • The new states are characterized by large partial widths (Bfs) to hadrons+J/y • Br(X(3872)rJ/y) > 4.3% (Isospin=1) • G(Y(3940)wJ/y) > 7 MeV (SU(3) octet) • G(Y(4260)p+p-J/y) > 1.6 MeV • There is no apparent transition at the D**D mass threshold

  32. Thank You

  33. Back-up slides

  34. Look at e+e-J/y D(D(*)) • Reconstruct a J/y & a D • use D0K-p+ & D+K-p+p+ • Determine recoil mass

  35. Inclusive BKx from BaBar Fully reconstructed B- tags ?

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